The present invention relates to a manipulating part of an endoscopic treatment tool that is to be inserted into a treatment tool insertion channel of an endoscope.
In general, an endoscopic treatment tool is designed such that a distal end operating section is driven with a manipulating part on an operator side through a manipulating wire passed through and axially movable with respect to a sheath inserted into a treatment tool insertion channel of an endoscope.
The manipulating part is generally equipped with a first finger retaining member that is attached to a cylindrical member connected to the proximal end of the sheath, and a second finger retaining member that is slidable relative to the cylindrical member and connected to the proximal end of the manipulating wire. The sliding motion of the second finger retaining member along the cylindrical member causes the axial motion of the manipulating wire.
In case of some treatment tools, such as an endoscopic forceps tool, which use a closely wound coil as the sheath, the manipulating stroke varies depending on the degree of bending of the sheath. Therefore, during the use of the tool, the manipulating stroke may be too short to perform sufficient operation, or excessively long, causing the buckling of the manipulating wire.
In case of a high frequency snare, a basket type grasping tool, etc. in which a plurality of elastically contractible and expandable wires are retracted into or protruded from the distal end of the sheath, the constant size of the expanded elastic wires is inconvenient for an operator to treat a polyp, a foreign matter or the like which has a different size.